Paul Ryan and his Republican supporters see the presidential election as a chance to educate voters about Medicare reform. Some claim that campaigns are not for educating, but for winning. That's only partially true. Campaigns still have great teaching value.

Claremont, Calif. — Mitt Romney’s choice of Rep. Paul Ryan of Wisconsin as his running mate could be a lesson on the educational value of campaigns. Mr. Ryan, the Republican chairman of the House Budget Committee, has taken detailed positions on issues such as Medicare and the national debt. He and his supporters see the race as a chance to educate the public about these subjects.

Howard Dean, former chair of the Democratic National Committee, is not so sure. “I always have told people campaigns are not for educating,” he said recently on ABC’s “This Week” program. “People who use campaigns as a means of educating lose the campaign,” he explained. “Now, they may go on to win a bigger race later on, but campaigns are not made for educating. And Ryan has to educate the country, and I don’t think that’s possible.”

First, the main goal of a campaign is not to educate but to win. And winning doesn’t always mean educating. Candidates can win by mobilizing certain voters or by stirring ugly passions. Some win by lying, which is the opposite of educating.

When candidates take a stand that most voters disagree with, they might try to prevail by changing the majority’s mind. This approach rarely works, at least with key issues. Opinions on such matters are resistant to change, especially in the short span of an election campaign. That’s the second way in which Dean is right.

His observation might not apply to Ryan, since some polls suggest that his proposal for shifting Medicare to a premium-support system is not as politically dangerous as Democrats hope.

The most important point to remember is not about Ryan in particular but about campaigns in general. While Dean is correct that campaigns are not mostly about education and that they seldom prompt instant conversions, they still have great teaching value.

Voter education is a side effect of campaigns, but it’s an important side effect. In the short run, it means that people on each side will know more. Even if they don’t change their minds, those minds will be better stocked.

Many will try to persuade their friends and neighbors, and in the longer run, public opinion may indeed shift. Howard Dean should know: His 2004 presidential race did not put him in the White House, but it did get people talking more critically about Iraq. Accordingly, it played a part in turning sentiment against the war over the next few years.

How does this education work?

Surprisingly, negative television ads can be an important resource. Vanderbilt University political scientist John Geer has found that negative spots tend to convey more policy substance than positive ones. Although voters dislike the term “negative,” a recent survey shows that most Americans think that ads focusing on contrasts or inconsistencies on issues are helpful.

Campaigns usually mix the policy information with chunks of distortion and personal invective – but that doesn’t make the information any less useful. In one race for the Senate, the incumbent hinted that his opponent was both a drinker and a traitor, and accused him of favoring a “war of extermination.” The contest, in 1858, was between incumbent Senator Stephen Douglas and challenger Abraham Lincoln. Notwithstanding the trash talk, their speeches and debates contained so much substance that we still study them.

True, the televised Obama-Romney debates in October will not be of that caliber. Each of the Lincoln-Douglas debates consisted of a 60-minute opening statement by one candidate, a 90-minute reply by the other, and a 30-minute rejoinder by the first. The candidates could marshal their evidence at a level of detail that would be far beyond today’s debate formats, which keep candidates from speaking for more than a few minutes at a time.

Even so, the debates will still provide viewers with glimpses of what the two sides intend to do. Ninety seconds should be enough time to explain whether a tax increase is necessary, and if so, who should bear it.

Whereas debates provide mini-lessons on political issues, the Internet supplies long-form courses. Campaigns, advocacy groups, and news organizations provide Americans with more access to more kinds of material – videos, speech texts, position papers – than was ever before possible in history. In 2010, the Pew Research Center found, about three-fourths of adult Internet users went online to get news or information about the midterm elections, or to take part in the campaigns.

Americans are not just passively absorbing political education: Many of them deserve decent grades for class participation. Among users of social networking sites, 37 percent post political material at least occasionally.

After losing the presidency to Dwight Eisenhower, Adlai Stevenson spoke with a supporter who told him that his campaign had educated the people. Stevenson replied: “But a lot of people flunked the course.” In November, partisans will come to different conclusions as to whether voters have passed the 2012 version. But one thing is clear: Course materials are abundant.